We are developing a monkey model of peripheral vascular disease with a unilateral femoral artery occlusion. Blood flow to the muscle is quantified with contrast-enhanced ultrasound. Half of the monkeys will exercise throughout the study. The first cohort of monkeys is walking 30 minutes three times per week. Baseline data collection is on-going and includes: general activity, body composition analysis, serum sampling, maximal force generation and muscle fatigue measures, vascular ultrasound, and muscle biopsies.